Which Is The Best Fish Aquarium On The UK Market?

A good fish aquarium should be study, leak-free and durable. Size is also an important consideration. The best size depends on the type and number of fish you plan to keep.

Some fish tanks come as a complete kit, with all the components you need to get started. Others include just the glass casing, letting you choose your own equipment.

In this buying guide, we recommend the best fish aquariums on the UK market, ranging from large aquariums to small desktop fish bowls.

If you want to see our recommendation straightaway, here is a quick summary:

Best Fish Aquariums (UK Market)

Our Top Pick

Diversa Aquarium Professional Fish Tank, 300L

Diversa Aquarium Professional Fish Tank, 300L

  • Extra-large capacity
  • Includes aquarium mat
  • Sturdy, leak-proof construction
  • Good price for an aquarium of its size


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Small Tank

Aqueon Standard Glass Rectangle Aquarium, 38L

Aqueon Standard Glass Rectangle Aquarium, 38L

  • Perfect for small aquariums
  • Ideal for small spaces
  • Clear silicone joints
  • Sturdy and durable construction


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Mini Tank

Fish 'R' Fun Hexagonal Tank, 21.6 Litres

Fish ‘R’ Fun Hexagonal Tank, 21.6 Litres

  • Perfect for a mini-aquarium
  • Great for small spaces like an office desk or bedside cabinet
  • Includes filter, bio balls and lights


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Unique Design

Fish R Fun Deco O Fish Tank, 20L

Fish R Fun Deco O Fish Tank, 20L

  • Great for small spaces
  • Unique fish bowl shape
  • Comes as a complete ready-to-use kit


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Midsize Tank

Ciano 2ft COLDWATER Aqua 60 LED Glass Aquarium, 58L

Ciano 2ft COLDWATER Aqua 60 LED Glass Aquarium, 58L

  • Great choice for a mid-size aquarium
  • Comes with some equipment
  • Sturdy glass construction
  • Closed design to reduce evaporation and maintenance


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Features to Consider When Choosing a Fish Aquarium

A. Size

Aquariums range from small 20-litre tanks to large aquariums with hundreds of litres in capacity. The best size depends on the type of fish you plan to keep as well as the number of fish.

Fish require adequate space to swim and play. A too-small tank can lead to wild fluctuations in pH and high levels of waste. This can stress the fish, and lead to death.

This may seem non-intuitive, but a larger aquarium (over 75 litres) is the best if you are just starting out. It’s easier to maintain aspects like pH and temperature within the right range in a large aquarium. There’s also a lower risk of toxic waste build-up. Your fish will be less stressed too.

If you don’t mind the extra maintenance work, you can get a smaller aquarium, as small as 20 or 30 litres.

Also, keep in mind the amount of space you have for the aquarium. A large fish tank may not be suitable for an apartment or a small office. For smaller spaces, there are mini-aquariums that are perfect for one or two fishes or small fish types like betta fish or guppy fish.

B. Construction

When it comes to material, glass aquariums are better in many ways than those made with acrylic.

Acrylic aquariums are lighter, but they scratch easily. They are also expensive and don’t age well (the get brittle and yellow over time).

Glass aquariums are highly scratch-resistant, they are inexpensive compared to acrylic fish tanks and they age well. Their only downside is the high risk of damage from impact.

That’s why it is important to get a sturdy and well-made glass aquarium. Get one with thick glass walls that can withstand the weight of water and rocks.

It should also be leak free. Aquariums use silicone to create leak-proof joint.

C. Design

Standard fish aquariums are rectangular. These are easy to work with especially when it comes to adding extra equipment like a filter, lights, or a fish feeder. It’s also easier to decorate a rectangular fish tank with rocks and plants.

If you prefer a unique design, get those with a bowl or orb design. Keep in mind that these designs are typically smaller, and thus require more work to maintain. You are also limited in the type and number of fish you can keep.

One other design aspect to consider is the lid. Traditional aquariums are closed. This has several advantages including reducing water evaporation and making maintenance easier.

A closed fish tank is also better for plants that need to stay fully immersed in water or if you plan to keep fish like koi, goldfish or killifish that are known to jump out of the aquarium.

Open fish tanks without a lid are getting popular. Some people love how they look. You can have some plants growing above the water and some decorations like rocks or driftwood can peak out of the water.

The problem with open fish tanks is maintenance. Because of evaporation, you have to top up the water daily, while being careful to maintain proper water chemistry.

D. Equipment

Finally, check what equipment, if any, comes with the aquarium.

Some people prefer a basic glass casing that they can customize to their needs and preferences. You add your own lights, filter, decorations and other equipment.

But if you want to get started right away, look for an aquarium that comes with most of the stuff you need including a filter and lighting.

Top 5 Reviews

1. Diversa Aquarium Professional Fish Tank, 300L

Our Top Pick
9.4/10 Our Score

This is the best choice if you are looking for a large fish aquarium. The 300L (80 gal) capacity is adequate for holding a number of fish. Going with the 1inch-per-gallon fish tank rule, the Diversa 80-gallon aquarium can comfortably hold 80 inches of fish.

The actual number of fish will depend on their size.

This package includes just the glass casing. It’s pretty big, so make sure you have the space for it. It measures 120cm long by 50cm wide by 50cm high.

Also, keep in mind that it’s going to be heavy once you fill it with water. The water only will weigh close to 300kg. Add to this the weight of the glass, decorative rocks, plants and equipment and you can see why it’s important to have a level and sturdy surface to place the aquarium on.

If you plan to place it on a cabinet, check its weight limit to avoid a disaster.

The glass aquarium is made with double silicone joints for added sturdiness and to prevent leaks. But some customers wish they used clear silicone. The black silicone edges stand out too much.

2. Aqueon Standard Glass Rectangle Aquarium, 38L

Small Tank
9.2/10 Our Score

This is the best choice if you are looking for a small and inexpensive rectangular aquarium.

The Aqueon glass aquarium has a capacity of 10 gallon (about 38L) and measures 51.4cm X 26.7cm X 32cm. This makes it a good choice for small spaces like apartments, bedrooms or dorm rooms.

It’s also a good choice if you want to keep only a few fish. It’s especially suitable for small fish like betta.

The sturdy glass casing comes with clear silicone joints and black trimming at the top and bottom. The aquarium is ideal for both freshwater and saltwater applications.

Only the casing is included in the package. You have to supply your own gravel, rocks, plants, lighting, filter and other components. The upside is that you have the freedom to decorate the aquarium exactly the way you want.

3. Fish ‘R’ Fun Hexagonal Tank, 21.6 Litres

Mini Tank
9.1/10 Our Score

Looking to set up a mini aquarium? We recommend the Fish ‘R’ Fun Hexagonal Tank. It holds jut 21.6L of water and is small enough to put on your work desk or bedside stand. The tank is fully enclosed to minimize evaporation and maintenance.

The Fish ‘R’ Fun Hexagonal Tank comes as an almost complete kit. In addition to the glass tank, you get a tank top filtration system with an easy change wool and activated carbon filter cartridge.

You also receive bio balls that hold beneficial bacteria, LED lights in a moisture-proof singular polycarbonate tube and a large hinged cover that provides easy access to the filter and tank.

All you need to buy is gravel and a few live or artificial plants. You can also add an air pump an air stone if you think the fish tank requires oxygenation or to create a beautiful bubbling effect.

4. Fish R Fun Deco O Fish Tank, 20L

Unique Design
8.9/10 Our Score

This is another good choice if you are looking for a mini aquarium. The Deco O fish tank, also from Fish ‘R’ Fun, has a 20-litre capacity making it ideal for small fish like betta and small spaces.

The unique bowl design makes it especially suitable for decorating your work desk, bedside cabinet or a corner of the living room.

Similar to the Fish ‘R’ Fun Hexagonal Tank, the Deco O comes with some extra components. They include a filtration system hidden cleverly within a stack of decorative stones, lighting, gravel, a plastic plant and a pump.

You are ready to fill it with water and fish out of the box. Note that both the filter and lighting are USB-powered.

5. Ciano 2ft COLDWATER Aqua 60 LED Glass Aquarium, 58L

Midsize Tank
8.8/10 Our Score

This is the best choice if you are looking for a mid-size aquarium that’s neither too big nor too small. The 58L capacity is enough for 15-25 small fish or a couple bigger fish like Gourami.

The Ciano glass aquarium is rectangular with a plastic trim and lid. You can remove the lid to access the tank. There’s also a hatch on the lid for adding fish food to the water, either manually or using a fish feeder.

The aquarium comes with several extras including LED lighting, a biological filter, a Water Clear filter cartridge and a pump.

All you need to get started is substrate, some plants and rocks and maybe a heater if you live in a cold area.